For a long time now in Windows I have used Text Crawler 3 (see here) for find and replace. It is free for non-commercial use, and extremely useful where, as in my case, hundreds of files have needed such alterations.

Further to my post above, I have also used the program mentioned just to find which parts of which pages in a project file need changing. I exported the project file to the hard drive and used the program mentioned with just the find facility to get a list of the finds. I could then use that list to guide me when making the changes in RSD.